After the rest i.e. all those verbs not falling under any one of the previous provisions, the terminations of the parasmaipada are used, in marking the agent i.e. in the active voice.,
The rules of Atmanepada have been declared in the preceding 66 sutras, 1.3.12 to 1.3.77. The terminations of the Parasmaipada, which are the general verbal terminations, will come everywhere else, that is to say, where its operation is not debarred by any one of the preceding aphorisms. The present sutra declares this universal rule. The word sesha or the rest, means that which is the residue after the application of all the previous restrictive rules. Thus it was declared by sutra 1.3.12 ante that a root having an Anudatta vowel or a ङ as it, will take Atmanepada termisations. As आस्ते शेते. The converse of this will take parasmaipada terminations, namely all verbs which do not have an anudatta accent or a ङ as it. Thus याति 'he goes,' वाति 'it blows.' It has been declared by sutra 1.3.17 that the root विश when preceded by नि takes Atmanepada terminations, as निविशते. When not preceded by नि but any other preposition, it will take the parasmaipada termination. As आविशति, प्रविशति.
Why do we say \when marking the agent\? For when used in the passive voice the root will take the Atmanepada termination. As पच्यते 'it is cooked', गम्यते 'it is gone.'
Why is not parasmaipada used when the verb is employed reflexively ? As in the following example :- पच्यते ओदनः स्वयमेव 'the food cooks of itself.' Because in the present sutra the word कर्तरि of sutra 1.3.14 ante is to be read in by anuvritti, so that, in fact there are two कर्तरि in this aphorism which thus means \when the agent of the verb is an agent pure and simple then parasmaipada is employed.\ While when a verb is used reflexively (कर्म्मकर्तरि) the agent of the verb is also, in one aspect, the object of the verb; and it is therefore, that in reflexive verbs the Atmanepada terminations are employed.,